Novel system for diagnosis of stenosis allows prioritisation of critical cases

24th April 2009

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A new automated system designed for the interpretation of coronary computed tomography angiography (CCTA), helps radiologists determine which cases are high priority and should be read first, according to a study performed at Thomas Jefferson University, Philadelphia, USA.

The study included 100 CCTA studies submitted for evaluation using the new automated system (COR Analyzer II Software, Rcadia Medical Imaging). “The software detected 10/13 patients with artery stenosis 50% or greater and correctly identified 59/80 patients with less than 50% artery stenosis,” said Dr Shaoxiong Zhang, lead author of the study. The negative predictive value for the study population was high, 95%,” said Zhang.

This new technology offers promising results for the diagnosis of stenosis in the major coronary arteries, although “more research needs to be done to further improve the accuracy of the software in identifying significant disease,” said Zhang. “Study interpretation using the automated interpretation of CCTA studies will allow for shorter reading times in negative cases and reduced response times in positive cases,” he said.

“In urban areas there are high demands to provide 24/7/365 day coverage and cardiac imaging may not be available during nights and weekends. Rural area, outpatient diagnostic centres may be lacking cardiac imaging experts. Preliminary study interpretation using the new rapid, automated interpretation system may potentially allow for better prioritisation of cases for evaluation by the expert leader,” said Zhang.

This study will be presented at the 2009 American Roentgen Ray Society Annual Meeting in Boston, on Monday, 27 April.

Another study that will be presented at the ARRS meeting on Monday showed that using cardiac CT to diagnose low risk patients with chest pain is significantly cheaper – 44% less than the standard of care – and can decrease the length of hospital stay up to 20 hours.

Fifty three low-risk chest pain patients were compared by using results from a cardiac CT based workup and a traditional standard of care workup using nuclear stress testing. “Nothing was cut from the standard of care workup,” said Janet May, University of Washington, Seattle, USA, lead author of the study.

“The current emergency department standard of care workup for low risk chest pain patients often involves serial cardiac enzymes, serial ECGs and a nuclear cardiac stress test. Such a workup can take up to 30 hours and is expensive. The mean cost for the SOC workup in this study was US$7,597,” said Janet. “With new lower dose cardiac CT options available that lower the patient radiation dose, patients get a faster evaluation and are discharged much sooner with a cardiac CT; in less than six hours,” she said.

“Once you know the case is a low risk patient with chest pain, the sooner the cardiac CT is done, the better. “Speed results in cost savings without compromising accuracy,” said Janet. “Emergency rooms across the nation are struggling with congestion and escalating cost issues. Over six million patients present to US emergency rooms each year with chest pain and the majority of these are low risk. Dealing with these patients faster and with greater cost effectiveness is a big step toward ameliorating congestion and spiraling cost,” she said.